The incidence and treatment of radial head subluxation were evaluated in emergency room and private office settings. Factors associated with recurrence and with successful reduction were identified, and ways to prevent this common injury were sought. Of 54 reductions during which a click was either felt or heard, all but one reduction resulted in reuse of the arm within 30 minutes. Of 13 reductions in which a click was neither felt nor heard, only four reductions resulted in reuse of the arm within 30 minutes. A supination maneuver resulted in reuse of the arm within 30 minutes in all 27 patients seen two or more hours after injury vs 85% (34/40) of patients seen less than two hours after injury. Remanipulation 12 to 106 hours later resulted in reuse of the arm in all those children who had failed to respond to previous treatment.